Gardai have made a fresh appeal for information from any witnesses who may have information about the death of a 54-year-old grandmother who died in suspicious circumstances after being assaulted last July.
Carol McAuley (54), of Ballybough Road in Dublin's north inner city, who had spent almost a month in a coma in hospital with severe haemorrhaging on the brain, died on August 21, 2014.
Sources have revealed that while Ms McAuley had "severe underlying health issues", she was still the victim of a serious assault before her death.
The case is being investigated by officers based at Mountjoy Garda Station and it has emerged that four people, including two women, have been arrested as part of the long-running probe.
A senior source told The Herald: "This has been a very tricky case and it has not been helped by a lack of co-operation from some key witnesses who ended up having to be arrested last October."
"Ms McAuley was the victim of an assault before her death but gardai have not yet been able to establish exactly what happened to her.
"She was taken to hospital on the morning of July 25 last and the investigation team is very keen to speak to anyone who came across this woman in the days leading up to her being hospitalised.
"There's a possibility that she may have been assaulted before she went into the flat in which she was found and everything is still being looked at.
"This woman's family are completely devastated about her death and are still looking for answers," the source added.
A file on the case has been sent to the Director of Public Prosecutions (DPP) in relation to the arrested suspects but it is understood that it is "unlikely" there will be charges in the case unless gardai receive more information.
Ms McAuley was found in her bed in the early hours of July 25 with injuries to her face and head. She also had marks around her eyes and ears.
Gardai were given an account that the day before she was taken to hospital she had been involved in an altercation.
When she woke up on July 25 complaining that she felt unwell, an ambulance was called.
"She had suspected severe haemorrhaging on the brain and when she arrived in hospital, her condition was described as critical and it did not get any better," the source added.
The dead woman had "serious underlying health problems" connected to alcohol abuse, which are linked to her death. However, the post-mortem found that an assault, including head injuries, was also a contributory factor in her death.
She had worked as a cleaner in a local community centre for years and her family, including several grown-up children, lived nearby.
After her death, Independent councillor Nial Ring said Ms McAuley was called "one of life's givers".